﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Reflection;
using System.Data;

namespace 开单.ComMethod
{
    public delegate bool AsyncEventHandler(DataTable dt, string FileName);
    public class ExportToExcel
    {
        public delegate void MethedEndEventHandler();
        public static event MethedEndEventHandler MethedEndEvent;
        /// <summary>
        /// 对外的导出方法
        /// </summary>
        /// <param name="dgv"></param>
        public static void MangerExport(DataTable dt)
        {
            //申明保存对话框
            SaveFileDialog dlg = new SaveFileDialog();
            //默然文件后缀
            dlg.DefaultExt = "xls ";
            //文件后缀列表
            dlg.Filter = "EXCEL文件(*.XLS)|*.xls ";
            //默然路径是系统当前路径
            dlg.InitialDirectory = Directory.GetCurrentDirectory();
            //打开保存对话框  
            if (dlg.ShowDialog() == DialogResult.Cancel) return;
            AsyncEventHandler asy = DataGridViewToExcel;
            IAsyncResult ia = asy.BeginInvoke(dt, dlg.FileName, MethodCompleted, asy);
        }

        /// <summary>
        /// 对外的导出方法
        /// </summary>
        /// <param name="dgv"></param>
        public static void MangerExport(DataGridView dgv)
        {
            DataTable dt = dgv.DataSource as DataTable;
            MangerExport(dt);
        }

        /// <summary>
        /// 导出完毕后激活事件让外面知道
        /// </summary>
        /// <param name="asyncResult"></param>
        private static void MethodCompleted(IAsyncResult asyncResult)
        {
            if (MethedEndEvent != null)
            {
                MethedEndEvent();
            }
        }

        /// <summary>
        ///方法，导出DataGridView中的数据到Excel文件
        /// </summary>
        /// <remarks>
        /// add com "Microsoft Excel 11.0 Object Library"
        /// using Excel=Microsoft.Office.Interop.Excel;
        /// using System.Reflection;
        /// </remarks>
        /// <param name= "dgv"> DataGridView </param>
        private static bool DataGridViewToExcel(DataTable dt, string FileName)
        {
            #region 验证可操作性

            //返回文件路径
            string fileNameString = FileName;
            //验证strFileName是否为空或值无效
            if (fileNameString.Trim() == " ")
            { return false; }
            //定义表格内数据的行数和列数
            int rowscount = dt.Rows.Count;
            int colscount = dt.Columns.Count;
            //行数必须大于0
            if (rowscount <= 0)
            {
                MessageBox.Show("没有数据可供保存 ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return false;
            }
            //列数必须大于0
            if (colscount <= 0)
            {
                MessageBox.Show("没有数据可供保存 ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return false;
            }
            //行数不可以大于65536
            if (rowscount > 65536)
            {
                MessageBox.Show("数据记录数太多(最多不能超过65536条)，不能保存 ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return false;
            }
            //列数不可以大于255
            if (colscount > 255)
            {
                MessageBox.Show("数据记录行数太多，不能保存 ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return false;
            }

            //验证以fileNameString命名的文件是否存在，如果存在删除它
            FileInfo file = new FileInfo(fileNameString);
            if (file.Exists)
            {
                try
                {
                    file.Delete();
                }
                catch (Exception error)
                {
                    MessageBox.Show(error.Message, "删除失败 ", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                    return false;
                }
            }
            #endregion
            Microsoft.Office.Interop.Excel.Application objExcel = null;
            Microsoft.Office.Interop.Excel.Workbook objWorkbook = null;
            Microsoft.Office.Interop.Excel.Worksheet objsheet = null;
            try
            {
                //申明对象
                objExcel = new Microsoft.Office.Interop.Excel.Application();
                objWorkbook = objExcel.Workbooks.Add(Missing.Value);
                objsheet = (Microsoft.Office.Interop.Excel.Worksheet)objWorkbook.ActiveSheet;
                //设置EXCEL不可见
                objExcel.Visible = false;
                //向Excel中写入表格的表头
                int displayColumnsCount = 1;
                for (int i = 0; i <= dt.Columns.Count - 1; i++)
                {
                    //if (dt.Columns[i].Visible == true)
                    //{
                    objExcel.Cells[1, displayColumnsCount] = dt.Columns[i].ColumnName.Trim();
                    displayColumnsCount++;
                    //}
                }
                //设置进度条
                //tempProgressBar.Refresh();
                //tempProgressBar.Visible = true;
                //tempProgressBar.Minimum = 1;
                //tempProgressBar.Maximum = dgv.RowCount;
                //tempProgressBar.Step = 1;
                //向Excel中逐行逐列写入表格中的数据
                for (int row = 0; row <= dt.Rows.Count - 1; row++)
                {
                    //tempProgressBar.PerformStep();
                    displayColumnsCount = 1;
                    for (int col = 0; col < colscount; col++)
                    {
                        //if (dt.Columns[col].Visible == true)
                        //{
                        try
                        {
                            objExcel.Cells[row + 2, displayColumnsCount] = dt.Rows[row][col].ToString().Trim();
                            displayColumnsCount++;
                        }
                        catch (Exception)
                        {
                        }
                        //}
                    }
                }
                //隐藏进度条
                //tempProgressBar.Visible = false;
                //保存文件
                objWorkbook.SaveAs(fileNameString, Missing.Value, Missing.Value, Missing.Value, Missing.Value,
                Missing.Value, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlShared, Missing.Value, Missing.Value, Missing.Value,
                Missing.Value, Missing.Value);
                MessageBox.Show(fileNameString + "\n\n导出完毕! ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return true;
            }
            catch (Exception error)
            {
                MessageBox.Show(error.Message, "警告 ", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return false;
            }
            finally
            {
                //关闭Excel应用
                if (objWorkbook != null) objWorkbook.Close(Missing.Value, Missing.Value, Missing.Value);
                if (objExcel.Workbooks != null) objExcel.Workbooks.Close();
                if (objExcel != null) objExcel.Quit();
                objsheet = null;
                objWorkbook = null;
                objExcel = null;
            }

        }
    }
}
